Sorry I edited my comment. I think the difference, not just being able to comment, but is being able to post. Like not everyone is able to post an article in Gizmodo but anyone can post a video on YouTube, or a story on Instagram.
This is just my own thoughts on it. I don't actually know what the official definition of social media is.
Definitely in transportation and healthcare. Probably in education once Trump gets rid of the Department of Education.